The U.S. Food and Drug Administration announced today that it has approved the 2012-2013 influenza (flu) vaccine formulation for all six manufacturers licensed to produce and distribute the vaccines in the United States.

Each year experts from the FDA, the World Health Organization, the Centers for Disease Control and Prevention (CDC), and other public health experts study influenza virus samples and global disease patterns to identify virus strains likely to cause the most illness during the upcoming flu season.

Based on that information and the recommendations of the FDA’s Vaccines and Related Biological Products Advisory Committee, the strains selected for inclusion in the 2012-2013 flu vaccines are:

A/California/7/2009 (H1N1)-like virus

A/Victoria/361/2011 (H3N2)-like virus

B/Wisconsin/1/2010-like virus.

While the H1N1 virus is the same as what was included in the 2011-2012 influenza vaccines, this year’s influenza H3N2 and B viruses differ from those in the 2011-2012 influenza vaccines.

Vaccination remains the cornerstone of preventing influenza, a contagious respiratory disease caused by different influenza viruses infecting the nose, throat and lungs. This year’s seasonal vaccines will provide protection against the three influenza virus strains that global surveillance indicates are likely to be the most common strains circulating during the upcoming season.

There is always a possibility of a less than optimal match between the virus strains predicted to circulate and the virus strains that end up causing the most illness. However, even if the vaccine and the circulating strains are not an exact match, the vaccine may reduce the severity of the illness or may help prevent influenza-related complications.

“The best way to prevent influenza is by getting vaccinated each year,” said Karen Midthun, M.D., director of the FDA’s Center for Biologics Evaluation and Research. “It is especially important to get vaccinated this year because two of the three virus strains used in this season’s influenza vaccines differ from the strains included in last year’s vaccines.”

According to the CDC, between 5 percent and 20 percent of the U.S. population develops influenza each year. This leads to more than 200,000 hospitalizations from related complications. Influenza seasons are unpredictable and can be severe, with annual influenza-related deaths ranging from a low of about 3,000 to a high of 49,000 people in the U.S. The CDC’s Advisory Committee on Immunization Practices, recommends that everyone six months of age and older receive an annual influenza vaccine.

Health care providers play an important role in advising their patients to get vaccinated each year and should also protect themselves, their patients, their family, and the community from influenza by getting vaccinated.

The manufacturers licensed to produce the nation’s 2012-2013 flu vaccines and the brand names of the vaccines for the upcoming flu season are:

Afluria, manufactured by CSL Limited;

Fluarix, manufactured by GlaxoSmithKline Biologicals;

FluLaval, manufactured by ID Biomedical Corporation;

FluMist, manufactured by MedImmune Vaccines Inc.;

Fluvirin, manufactured by Novartis Vaccines and Diagnostics Limited; and

CDC: Seasonal Influenza – Who should get vaccinated against influenza (Flu)

The FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by assuring the safety, effectiveness, and security of human and veterinary drugs, vaccines and other biological products for human use, and medical devices. The agency also is responsible for the safety and security of our nation’s food supply, cosmetics, dietary supplements, products that give off electronic radiation, and for regulating tobacco products.